We've already had some discussions about this - here's one from September: [webmasterworld.com...]

There's not a lot of solid information from Google about the exact "how". My assumption is that it works something like the widely used Flesch-Kincaid reading ease assessments (used in MS Word). That would mean important factors are average number of words per sentence, and average number of syllables per word.

@philipjterry, outside of playing around with reading level options, mostly after the first Panda release, I haven't given it a lot of consideration to it as a search factor.

I feel pretty sure that Google is calculating reading level for some reason - it's not just some curiosity. At the very least, they are monitoring this as a metric to see how it might be useful. We know they monitor a lot that they do not directly use in the algo at the present moment.

As a content creator, I use reading level a lot - and as an editor I ask writers to aim for relatively low reading levels (8th grade is great, 10th grade is OK). Even in high academia, there's often no reason for convoluted sentences and overly erudite word choices.

Interesting... By adding the word 'obfuscation' the score seems to have more than doubled... It appears to be very sensitive.

While doing target group research this would be a very complimentary topic to mesh in at the same time. Could also be a great way of starting with a broad term to find and learn new terminology. For some audiences (take chefs as an example) new ideas often spawn from new words or foreign terminology - which can create a new perspective. They may be professional but not familiar with all those terms...

Having said that is 'reading level' focused on filtering the english itself or the categories level of competence by looking at terms like Nouns?

I default to the advanced reading level because I like a challenging read which will stretch my imagination beyond my comfort zone...

I'm imagining Google is putting a heavy weight on terminology. Say for example i search cooking related terms covering areas like "sashimi" or "passata" start appearing - those would be better classified under advanced...? Compared to an introductory passage about Japanese style food and Italian style food which would fall under beginners...

I'll read the link tangor kindly referred tonight and give it some thought.

I've spent some time checking out search targeting for a client's site, and noticed that changing core keywords in a query could have huge effects on the types of sites and the Google reading level profile returned.

My guess is that the search queries bring up sites intended (consciously or unconsciously) for the audience that would use them, and the entire vocabulary mix of the page and the intention of the site relates to the query. So this becomes as much a demographic targeting question as a search targeting question.

We discussed something similar in the early days of Panda with regard to health query results....

- a search for [diseasename symptoms] or [diseasename treatment] would give you high quality clinic and public health sites...

- whereas, a search for [how can I tell if I have diseasename] or [what to do if I have diseasename] brought up a great many content farms.

Google may ultimately calibrate reading level preferences further via personalization, and will probably do everything possible to determine how these preferences affect other preferences. I think it's much more complex than simply educational level, though. Slang terms, for example, often skew Google's tool toward "basic" level, but knowledge of slang can be highly specialized knowledge.